Electromagnetic change-speed gear



Junk! 22, 1954 I J. MAURICE E ELECTROMAGNETIC CHANGE-SPEED GEAR FiledFeb. 18, 1952 I If K ,V, w E

w A J Patented June 22, 1954 ELECTROMAGNETIC CHANGE-SPEED GEAR JeanMaurice, Paris, France, assignor to Societe Anonyme Francaise du Ferodo,Paris, France Application February 18, 1952, Serial No. 272,161

Claims priority, application France February 19, 1951 4 Claims.

5 The present invention has for its object an improvement in theoperation of electromagnetic :change-speed gears.

v A serious inconvenience with such gears, which comprise epicyclic geartrains of which the planet ,wheel carrying frames, the gear rings andthe sun .wheels can be coupled with fixed or movable electromagnets,resides in the fact that they in- ;clude rotatable members the inertiaof which 1 is comparatively high. The consequences of such a highinertia make themselves felt when the driver of a vehicle on which thegear is mounted is gearing up from dead point to first, then to secondgear, and so on. The transmission gear is "subjected toa jerk which mayresult in bouncing the vehicle forwards. Such a bouncing is particularlyfrequent in mechanisms including a hydraulic clutch since such anapparatus is designed to transmit a low torque even when run- ,ning at aslow speed.

The present invention affords a simple way of remedying theaforementioned inconvenience and of making an automobile rid of suchjerks.

The invention is concerned principally with an arrangement adapted, inthe dead point posi- .tion of the gear-selecting lever, so as toenergize one of the electromagnets in the change-speed gear as to obtainthe desired speed ratios between the various epicyclic trains instead ofallowing them to idle uncontrolled consequent to such variable actionsas the viscosity of the oil,

the frictional resistances encountered, and so on,

and this, in order to obtain, when gearing up or down, that the variousinertia in the changespeed gear and the dragging torque transmitted bythe hydraulic clutch will offset one another without reacting upon thetransmission gear of the vehicle.

An embodiment of the invention is illustrated diagrammatically and byway of example in the appended figure.

The change-speed gear shown is of the 4-speed type and comprises twoepicyclic gears mounted in series. The input shaft I is firm with a sungear l2 which meshes with the planet wheels 13 of a planet-carrier 2coaxial with shaft I. The

the left of said ring I5. The energizing circuit 'of the electromagnet 3is earthed at one end and is connected at the other end with the studsI1, I,

IS. The energizing circuit of the rotatable electromagnet 4 is earthedat one end and is connected at the other end with the contact studs 9,20, 2!, through a brush-and-slip-ring device I9 diagrammatically shown.

In series with the first epioyclic gear just described is mounted asecond epicyclic gear. The second gear comprises: first an internallytoothed annulus 22, coaxial with the shaft l, and integral with theplanet carrier 2 of the first epicyclic gear; second, a planet-carrier23 integral with the output shaft 5 of the change-speed. mechanism, thisplanet-carrier being provided with planet wheels I! in mesh with thetoothed annulus 22; and third, a sun-wheel 25 mounted freely rotatableabout the output shaft 5. This sun wheel 25 is integral with a sun discl0 having a suitable moment of inertia. The left side of this sun-disccan be engaged by a fixed electromagnet 6 secured to the housing I6. Onthe right side of the sun disc I0 is mounted an electromagnet 1, whichis rigid with the output shaft 5. The energizing circuit of the fixedelectromagnet 6 is earthed at one end, and is connected at the other endwith the studs 26, 21. The energizing circuit of the rotatableelectromagnet 1 is earthed at one end, and is connected at the other endto the studs 28, 30 through a brush-and-slip-ring device 3|diagrammatically shown.

Five feeding studs 33, 34, 35, 3B, and. 8, connected to the battery 31through an interrupter '38, are provided in the neighbourhood of thealready mentioned studs. The other terminal 0 the battery 31 is earthed.f

A control contactor secured to the gear-selecting lever (not shown) ofthe change-speed mechanism and displaceable inside a guide 39 is adaptedto engage simultaneously and to electrically connect to each other:

In a first position I, the studs 11, 2B and 33.

In a second position II, the studs I8, 28 and 34.

In a third position III, the studs 20, 21 and 35.

In a fourth position IV, the studs 2|, 30 and 36.

In a fifth intermediate position, or dead position D. P., the studs 8and 9.

The operation of the apparatus is as follows:

In each of the four positions I, II, III, IV, the contactor energizesone electromagnet in each of both epicyclic gears and gives a differenttransmission ratio between the input shaft I and the output shaft 5.

Thus, in position I, the electromagnets 3 and 6 are energized. In thefirst epicyclic gear, the

-=taLtedintegral withcthe input shaft I. end -.epicyc1ic gear, thesun-disc l9 and the sun rwheel'i25 :are then fixed, and the output shaftis *accordingly rotated at the reduced speed ratio -;.of thevfirst.epicyclic gear. zentc and in fact greater than the reduced ratiorofcth'e Ifirst epicyclic gear.

' In position IV, the .electromagnets 4 and l are: energized. Thecarrier. 2 is lockedintegral -i wi'th the input shaft 1. Theoutputshaftsis toothed ring [5 is then fixed, and this results in arotation of the planet carrier 2 at reduced speed. In the secondepicyclic gear, the sun, disc l and the sun wheel 25 are then fixed, andthis results in a rotation of the output shaft at reduced speed withregard to the planet carrier 2. Thefinal transmission ratio is theproduct of the reduced speed ratios of each epicyclic ear.

In position II, the electromagnets 3 and l are energized. In the firstepicyclic gear; the planet carrier 2 is rotated at reduced speed. .Inthesecond epicyclio gear, the sun disc 10 and the sun wheel 25 are thenmade integral with shaft and carrier 23. Accordingly-the-planetwheels IIare locked integral with their carrier Land this results in theactuating of the thus formed rigid assembly by the annulus 22 of carrier2 at the same speed as this carrier; In other terms, the transmissionratio of the whole mechanism is the: reduced speed 'ratio of the first:epicyclic .positionIII of the switch, the electromagfnetsxskand' 6 areenergized. The electromagnet 4 makes the ring [5 integral with :theinputishaft 4.. :Consequent1y,-the shaft I, the ring 55, the--:sun-wheel 7 52, the planet-wheels I3 and the 'pIanet-carrien-Z .arelocked together and are ro- In the see- This ratio is differflockedintegral with the toothed :armulus 22 of the carrier :2. This resultsin=a rotation of shaft :52 integral with shaft 1, that :is in:a directdrive.

lngithe fifth position DIP thewonlygelectm- If the input shaft 5 isactuated by the residualctorque the clutch, the internallytoothedsringcZZ, .roitatingrintegral with the input shaft '1' and in V-meshiwith the planet wheels 1 l, ,actuates these planet-wheels .ll:ln'the same direction of =:r.o-

tation, and that these planet wheels .-r.otaterthe As the driver shiftsto first gear all the revolving masses are instantaneously stopped-and,owingto the fact that they are rotated in opposite directions and thattheir inertiae are sub- 'stantially equal in view of the ratios betweenthe rotational speeds, they ofiset one another and onl cause the planetwheels I l to rotate without'actingupon the planet wheel carrying'framewhich is connected with the output shaft; consequently,

no impulse is transmitted to the vehicle. Q What I claim is:

1. A'change speed mechanism comprising: an

, "input shaftand an output shaft; a first epicyclic :gear comprising adriving member integral 'in rotation with the input shaft, aloCkablemem- Iber, and a driven member, a first electrcmagnet s-adaptedto render the lockable member: and I the --su-n wheellzfi .and the .sun.disc 1:0 thereverse .direction, at a higher speed thanthe annulus :22and the input shaft 1.

driven member of said first gear integral in rotation with the inputshaft, and a second electromagnet adapted to hold stationary thelockable member of said first gear and to rotate thus the driven memberwith a reduced gear ratio; a second epicyclic gear including adrivingmember integral in rotation with the driven member of the first gear, alockable member, and a driven member integral with the output shaft,

saidlockable member of the second gear being "adapted "torotate in thedirection opposite to that-of the driving member of the same gear whenthe .driven member is being held stationary, afirst electromagnetadapted to render the driving member and the lockable member of thesecond'gear integral in rotation with the output shaft, and a secondelectromagnet adapted to hold stationary the lockable member of thesecond gear and to rotate thus the output shaft with a reduced gearratio with regard, to the driving member of the second gear; four setsof contacts connected to the energizing circuits-of the electromagnets,each set of. contacts-being adapted, when its contacts are connectedwitheach other, to energize simultaneously one electromagnet of "the firstgear and one electromagnet of the second gear, the four said setsofcontacts corresponding respectively to the four possible combinationsof one e'lectromagnet of the first gear with one electromagnet of'thesecond gear, and accordingly to four transmission ratios between theinput shaftand the output shaft; a fifth set of contacts connected tothe energizing circuit of the first-electromagnet of the' fir'st gearand corresponding to neutral position, and means to connect-with eachother the contacts of each set successively, said fifth set of contactsmaking electrical connections, when ii-ts contacts are connected witheach other, to-energize only the first electromagne't of the first gear,which results, when the output shaft and-the driven member of the secondgear integral therewith are being held stationary and when the inputvshaft is being rotated, in drivingftogether with said input shaft allthe members ofthe' first gear and the driving member of the second gear,and in rotating in the reversedirection the" lockable member of thesecond gear; whereby the inertia of the lockable member of the second:gear counteracts that of the members rotating with the input shaft whenselected onesof said electromagnets are energized to provide drivingconnections'between said input-and output-shafts.

.2. A change speed mechanism comprisingz-an input shaft and an outputshaftpa first :epicyclic fgear comprising a driving member 'integraltinrotation with the input shaft, a lockable memher, and a driven member, afirst electromagnet adapted to render the lockable member andithedrivenzmernber of said first gear integral in rotation with the inputshaft and a second-' elec'tromagnet adapted to hold stationary thelockable member of said first gear and to rotate thus the.

with saidtoothed ring, a 'sunxdi scint'egralfin. *rotationavith said-sunwheel, .a first electromagnet adapted to render said toothed .ringzancl-.saidsun wheel integralsi-n rotation with'thespianet carrier and theoutput shaft, and a second electromagnet adapted to hold stationary thesun wheel and the sun disc integral therewith, and to rotate thus theoutput shaft with a reduced gear ratio with regard to the toothed ring;four sets of contacts connected to the energizing circuits of theelectromagnets, each set of contacts being adapted, when its contactsare connected with each other, to energize simultaneously oneelectromagnet of the first gear and one electromagnet of the secondgear, the four said sets of contacts corresponding respectively to thefour possible combinations of one electromagnet of the first gear withone electromagnet of the second gear, and accordingly to fourtransmission ratios between the input shaft and the output shaft; afifth set of contacts connected to the energizing circuit of the firstelectromagnet of the first gear and corresponding to neutral position,and means to connect with each other the contacts of each setsuccessively, said fifth set of contacts making electrical connectionswhen its contacts are connected with each other, to energize only thefirst electromagnet of the first gear, which results, when the outputshaft and. the planet carrier integral therewith are being heldstationary and when the input shaft is being rotated, in drivingtogether with said input shaft all the members of the first gear and thetoothed ring of the second gear, and in rotating in the reversedirection the sun wheel of the second gear and the sun disc integraltherewith; whereby the inertia of the lockable member of the second gearcounteracts that of the members rotating with the input shaft whenselected ones of said electromagnets are energized to provide drivingconnections between said input and output shafts.

3. A change speed mechanism comprising: an input shaft and an outputshaft; a plurality of epicyclic gears arranged in series between saidinput shaft and said output shaft, said plurality of epicyclic gearsincluding a plurality of electromagnets adapted for establishingconnections between determined members of said gears and for holdingstationary determined members of said gears; among the epicyclic gears alast gear including a driving member integral in rotation with thedriven member of the last but one gear, a lockable member, and a drivenmember integral with the output shaft, said lockable member of the lastgear being adapted to rotate in the direction opposite to that of thedriving member of the same gear when the driven member is being heldstationary, a first electromagnet adapted to render the driving memberand the lockable member of the last gear integral in rotation with theoutput shaft, and a second electromagnet adapted to hold stationary thelockable member of the second gear and to rotate thus the output shaftwith a reduced gear ratio with regard to the driving member of thesecond gear; a plurality of sets of contacts connected to the energizingcircuits of the different electromagnets of the mechanism, each set ofcontacts being adapted when its contacts are connected with each otherto selectively energize the electromagnets corresponding to one of thegear ratios of the mechanism; an additional set of contacts connected tothe energizing circuits of the epicyclic gears other than those of thelast gear and corresponding to neutral position, and means to connectwith each other the contacts of each set successively, said additionalset of contacts making electrical connections, when its contacts areconnected with each other, to cause a positive actuation in rotation ofthe driven member of the last but one epicyclic gear and of the drivingmember of the last gear, which results, when the output shaft and thedriven member of the last gear integral therewith are being heldstationary, and when the input shaft is being actuated in rotation, inrotating in the direction opposite to that of the driving member of thelast gear the lockable member of said last gear, whereby the inertiaforces of oppositely rotating members counteract each other whenselected ones of said electromagnets are energized to provide drivingconnections between said input and output shafts.

4. A change speed mechanism comprising: an input shaft and an outputshaft; a plurality of epicyclic gears arranged in series between saidinput shaft and said output shaft, said plurality of epicyclic gearsincluding a plurality of electromagnets adapted for establishingconnections between determined members of said gears and for holdingstationary determined members of said gears; among the epicyclic gears alast gear comprising an internally toothed ring integral in rotationwith the driven member of the last but one epicyclic gear and coaxialwith the output shaft, a freely rotatable sun wheel coaxial with theoutput shaft, a planet carrier integral with said output shaft andhaving planet wheels meshing simultaneously with said sun wheel and withsaid toothed ring, a sun disc integral in rotation with said sun Wheel,a first electromagnet adapted to render said toothed ring and said sunwheel integral in rotation with the output shaft, and a secondelectromagnet adapted to hold stationary the sun wheel and the sun discintegral therewith, and to rotate thus the output shaft with a reducedgear ratio with regard to the toothed ring; a plurality of sets ofcontacts connected to the energizing circuits of the differentelectromagnets of the mechanism, each set of contacts being adapted whenits contacts are connected with each other to selectively energize theelectromagnets corresponding to one of the gear ratios of the mechanism;an additional set of contacts connected to the energizing circuits ofthe epicyclic gears other than those of the last gear and correspondingto neutral position, and means to connect with each other the contactsof each set successively, said additional set of contacts makingelectrical connections,-

when its contacts are connected with each other, to cause a positiveactuation in rotation of the driven member of the last but one epicyclicgear and of the toothed ring integral therewith, which results, when theoutput shaft and the planet carrier integral therewith are being heldstationary and when the input shaft is being actuated in rotation, inrotating in the direction opposite to that of said toothed ring the sunwheel of the last gear and the sun disc integral therewith, whereby theinertia forces of oppositely rotating members counteract each other whenselected ones of said electromagnets are energized to provide drivingconnections between said input and output shafts.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,078,130 Edwards Apr. 20, 1937 2,084,522 Cotal June 22, 19372,395,459 Carnagua Feb. 26, 1946

